These rules use the OOB maps for AA50 and 42. They are current files.
Labor Camp House Rules and Piece
Once at War, Nations (of course Germany & Russia had them before WW2) created Labor Camps to assist with the War Effort.
Once at War with a Major Power and Owning at least (1) original territory from your opponent, you can build a Labor Camp. Must be built at Major Factory Site. Labor Camp will reduce cost by 1IPC on selective units (my house rule would be Infrastructure, like Railroads, Rail Stations, Oil Derricks, Air Fields, Ship Yards, Bunkers, etc) However, could be used on Aircraft or Artillery & Armor. Can be bombed and removed from play. Can be liberated. If Liberated piece is removed from play.
Cost: Depends on if you are playing 40,39 or 36 Game. 5-8IPC
the structure will be a little shorter then an oil derrick piece. I will have them on my website soon.
Looks like Japan built a Labor Camp in Korea